This study will look at the safety, tolerability and what the body does to CS-8958 given to 40 healthy volunteers 18-55 years old. CS-8958 is a dry-powder investigational drug that is breathed into the lungs through an inhaler device. The researchers will collect information about any problems that volunteers have while taking the drug and about changes in blood pressure and how the heart is working. Volunteers will have breathing tests, physical examinations, and blood samples collected for laboratory tests. The researchers will also look at how much of the medication travels throughout the body versus how much stays only in the lungs. Doses of the medication will be tested at one level and then at higher and higher levels after a safety committee reviews the safety and tolerability information on volunteers prior to the next higher dose being given. Each volunteer will participate for up to 6 weeks from initial screening to the follow up visit and spend 7 days in the clinic.